Temperature dependence of optical transitions in AlGaAs

Lourenço, Sidney Alves; Dias, Ivan Frederico Lupiano; Duarte, José Leonil; Laureto, Édson; Menêses, E.A.; Leite, J. R.; Mazzaro, I.

doi:10.1063/1.1367875

Cited by 55 publications

(40 citation statements)

References 30 publications

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“…72 624͒, as evidenced by a rapid linear redshift of the PL peak energies. 27,28 Polimeni et al 15 observed similar S-shaped PL peak energy behavior in the InGaNAs/GaAs QWs, which was interpreted as arising from the detrapping of strongly localized excitons, and subsequent motion of the excitons in weakly localized states, that lie relatively close to the band edge. The temperature at which this detrapping occurred was found to increase with the N concentration of the QW, indicating that the number and/or potential depth of the carrier trapping centers increase with increasing N concentration.…”

Section: Resultsmentioning

confidence: 77%

“…In the 40-100 K interval, a competition between the blueshift associated with the recombination of localized excitons and the regular redshift of the band-gap energy induced by the lattice thermal expansion and the temperature dependence of the electron-phonon interaction takes place. 27,28 These latter phenomena dominate the band-gap dependence at temperatures over 120 K ͑No. 72 637͒ and 150 K ͑No.…”

Section: Resultsmentioning

confidence: 99%

“…27,28 Figure 3 shows the PL peak energy as a function of temperature in the 9-296 K range. Figure 3 more clearly shows the red/blue/redshift of the PL peak energy in both samples.…”

Section: Resultsmentioning

confidence: 99%

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Effect of temperature on the optical properties of GaAsSbN/GaAs single quantum wells grown by molecular-beam epitaxy

Lourenço

Dias

Poças

et al. 2003

Journal of Applied Physics

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GaAsSbN/GaAs strained-layer single quantum wells grown on a GaAs substrate by molecular-beam epitaxy with different N concentrations were studied using the photoluminescence ͑PL͒ technique in the temperature range from 9 to 296 K. A strong redshift in optical transition energies induced by a small increase in N concentration has been observed in the PL spectra. This effect can be explained by the interaction between a narrow resonant band formed by the N-localized states and the conduction band of the host semiconductor. Excitonic transitions in the quantum wells show a successive red/blue/redshift with increasing temperature in the 2-100 K range. The activation energies of nonradiative channels responsible for a strong thermal quenching are deduced from an Arrhenius plot of the integrated PL intensity.

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Section: Resultsmentioning

confidence: 77%

Section: Resultsmentioning

confidence: 99%

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Effect of temperature on the optical properties of GaAsSbN/GaAs single quantum wells grown by molecular-beam epitaxy

Lourenço

Dias

Poças

et al. 2003

Journal of Applied Physics

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“…A recent work [29] pointed out that the Viña et al [25] and the Pässler [9] models are the most suitable ones to fit the temperature dependence either of the band-gap energy or of the excitonic transition energy. The Viña approach is defined by the expression:…”

Section: Theoretical Modelsmentioning

confidence: 99%

Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs

et al. 2004

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Photoluminescence and photoreflectance measurements have been used to determine excitonic transitions in the ternary AlxGa1−xAs alloy in the temperature range from 2 to 300 K. The effect of the thermal expansion contribution on the temperature dependence of excitonic transitions for different aluminum concentrations in the AlxGa1−xAs alloy is presented. Results from this study have shown that the negative thermal expansion (NTE) in the AlxGa1−xAs alloy, in the low temperature interval, induces a small blueshift in the optical transition energy. In the temperature range from ∼23 to ∼95 K there is a competition between the NTE effect and the electron-phonon interaction. Using the thermal expansion coefficient in the 2 -300 K temperature range, the thermal expansion contribution to GaAs, at room temperature, represents 21% of the total shift of the excitonic transition energy. After subtracting the thermal expansion contribution from the experimental temperature dependence of the excitonic transitions, in the AlxGa1−xAs alloy, the contribution to the electron-phonon interaction of the longitudinal optical phonon increases, relatively to the longitudinal acoustical phonon, with increasing Al concentration.

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“…O Al x Ga 1-x As possui um "gap" de energia maior que o GaAs e a estrutura criada forma uma região de confinamento bidimensional para os portadores de cargas, com níveis de energia discretos e característicos desse poço em particular. Alterando-se a concentração de Al nas camadas de Al x Ga 1-x As, modifica-se o "gap" de energia do material, sendo possível, inclusive, controlar os níveis de energia dos elétrons e dos buracos no poço quântico (LOURENÇO et al, 2001a(LOURENÇO et al, , 2001b. A figura 1 apresenta uma estrutura de PQS, o perfil do potencial criado pela mesma e a representação da função de onda eletrônica para o estado fundamental em um PQS finito.…”

Section: Poço Quântico Simplesunclassified

Poços Quânticos Duplos Acoplados.

Lopes¹,

Cesar

Duarte

et al. 2010

Semina: Tech. Ex.

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ResumoO progresso das técnicas de crescimento de materiais semicondutores possibilita a oportunidade de fabricação de novos dispositivos semicondutores que podem contribuir para o desenvolvimento da nanotecnologia. A confecção de heteroestruturas semicondutoras de alta qualidade permite a obtenção de novos efeitos baseados nas propriedades quânticas desses sistemas, os quais despertam grande interesse tecnológico, especialmente nos setores opto-eletrônico e de telecomunicações. Neste trabalho são discutidos alguns conceitos básicos relacionados a uma dessas heteroestruturas: o Poço Quântico Duplo Acoplado (PQDA). A dedução da expressão para a determinação dos níveis de energia de PQDAs é apresentada em detalhes. Os resultados obtidos através desta expressão são comparados com resultados experimentais obtidos através da técnica de fotoluminescência (PL), complementando o trabalho. Palavras-chave: Semicondutores. Poços Quânticos. Fotoluminescência. AbstractThe progress of the semiconductor growth techniques allows the opportunity to produce new semiconductors devices that may contribute to the development of the nanotechnology. The fabrication of semiconductor heterostructures with high quality allows the obtaining of new effects based on the quantum properties of those systems, which have stimulated great technological interest, especially on the optoelectronic and telecommunications fields. In this work some basic concepts related to one of those heterostructures are discussed: the Coupled Double Quantum Well (CDQW). The deduction of the expression for the determination of the energy levels in CDQWs is presented in details. The results obtained through this expression are compared with experimental results obtained through photoluminescence (PL) measurements, complementing the work.

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Temperature dependence of optical transitions in AlGaAs

Abstract: AlGaAs structures with different aluminum concentration (xϭ0.0, 0.17, 0.30, and 0.40͒ were characterized by photoluminescence and photoreflectance techniques. The temperature dependence of optical transitions in the temperature ranging from 2 to 300 K were investigated.

Cited by 55 publications

References 30 publications

Effect of temperature on the optical properties of GaAsSbN/GaAs single quantum wells grown by molecular-beam epitaxy

Effect of temperature on the optical properties of GaAsSbN/GaAs single quantum wells grown by molecular-beam epitaxy

Thermal expansion contribution to the temperature dependence of excitonic transitions in GaAs and AlGaAs

Poços Quânticos Duplos Acoplados.

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